Prostate-specific Antigen (PSA), Free:Total Ratio Reflex
Also known as: PSA Total:Free Ratio Reflex
Use
Measure the percentage of free (uncomplexed) PSA relative to the total amount of PSA in men with serum PSA concentrations between 4.0 and 10.0 ng/mL.
Special Instructions
Not provided.
Limitations
The interpretive guidelines for percent free PSA are based on a population of men with normal digital rectal exam (DRE) and total PSA between 4.0 and 10.0 ng/mL. These guidelines should not be applied to other populations. Patients taking finasteride may experience diminished levels of PSA, and the serum levels of both total and free PSA increase with prostate manipulation but free PSA levels return to normal quicker. The use of percent free PSA has no specific recommendations for populations other than those with normal DRE and PSA between 4.0 and 10.0 ng/mL.
Methodology
Immunoassay (ECLIA)
Biomarkers
% Free PSA
AnalyteFree PSA
AnalyteTotal PSA
Analyte
LOINC Codes
- 2857-1 - PSA SerPl-mCnc
- 12841-3 - PSA Free MFr SerPl
- 10886-0 - PSA Free SerPl-mCnc
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.
Collection Instructions
If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
EDTA plasma specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 3 days |
| Refrigerated | 3 days |
| Frozen | 14 days |
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